But there’s always been a tricky part: how do you validate those license keys without exposing your sensitive API credentials in your app’s code?

Our team has just shared a new tool to make this simple and secure: the SendOwl License Checking Proxy.

Why This Matters

Until now, merchants who wanted to validate license keys often had to build their own middle layer or took risks by calling the SendOwl API directly from their apps. The problem? If you embed your API credentials in client-side code, it’s vulnerable. Anyone who digs into the app could find them and impersonate you; a real security risk.

How It Works

The new proxy is a Cloudflare Worker—a lightweight, serverless function you can deploy to your own account in just a couple of clicks. Once it’s running:

• Your app sends license validation requests to the Worker.

• The Worker talks securely to the SendOwl API using your credentials (kept private).

• The Worker returns only the validation result (valid or invalid) to your app.

Your API key never touches your customer’s device, and you don’t have to write or maintain your own secure proxy.

Easy One-Click Deploy

We’ve made setting up the proxy as straightforward as possible:

1. Click “Deploy to Cloudflare.”

2. Enter your SendOwl API credentials into Cloudflare’s secure environment (never client-side).

3. Start validating license keys securely.

No servers to manage, no custom security layers required—just a fast, safe solution out of the box.

The Bottom Line

This update gives SendOwl merchants peace of mind and can save time: your API keys stay private, your licenses stay protected, and your developers don’t have to reinvent the wheel.

If you’re looking to use license keys to protect your products, we recommend setting up the new License Checking Proxy today. It’s the easiest way to keep your business secure while focusing on what you do best—creating.

👉 Get started with the License Checking Proxy

What It Does

Think of it like a secure middleman.

• Your customer’s app asks, “Is this license valid?”

• The proxy checks with SendOwl, safely behind the scenes.

• It then replies back with the answer: “yes, valid” or “no, invalid.”

The best part? Your private SendOwl credentials are never visible to anyone.



Why You’ll Love It

• Safe by default – Your API key is never exposed.

• One-click setup – No complicated tech required; just connect it to your SendOwl account through Cloudflare.

• Set it and forget it – Once deployed, it just works.

The Result

You get peace of mind, your products stay protected, and you don’t have to worry about your customers poking around in places they shouldn’t.

👉 Try the new License Checking Proxy today — it only takes a couple of minutes to set up, and you’ll instantly have stronger protection for your business.

Developer Quick Start

1. One-click deploy to your Cloudflare account.

2. Enter your SendOwl API key and secret into Worker secrets.

3. Your app can now safely call yourworker.subdomain.workers.dev to validate licenses.

The One-click deploy process deploys to your Cloudflare account.

As a Cloudflare worker, you can make use of other Cloudflare features like rate-limiting or their Web Application Firewall to harden the endpoint and protect it from abuse. Is the proxy missing something you need? As the code is forked to your Github account, you can modify the code to make it work for your specific case.

When you’re up and running, you can test a license by sending 

Sample request:

curl -X POST "https://yourworker.subdomain.workers.dev" \

-H "Content-Type: application/json" \

-d '{"license_key":"YOUR_LICENSE","product_id":"YOUR_PRODUCT_ID", “order_id”: “YOUR_ORDER_ID”}'



Why This Matters

• Secure by design – No exposed API keys.

• Fast to deploy – Zero infrastructure, one-click setup.

• Developer-friendly – Works out of the box; customizable if you want to extend.

This makes license validation both easier and safer for every merchant.

Check out the GitHub repo and start securing your license validation in minutes.